A Lysosome-Activated Tetrahedral Nanobox for Encapsulated siRNA Delivery

Triangle-toothed gear occlude-guided universal nanotechnology constructs 3D symmetric DNA polyhedra with high assembly efficiency for precision cancer therapy

Chemotherapy is commonly used to treat malignant tumors. However, conventional chemotherapeutic drugs often cannot distinguish between tumor and healthy cells, resulting in adverse effects and reduced therapeutic efficacy. Therefore, zigzag-shaped gear-occlude-guided cymbal-closing (ZGC) DNA nanotechnology was developed based on the mirror-symmetry principle to efficiently construct symmetric DNA polyhedra. This nanotechnology employed simple mixing steps for efficient sequence design and assembly. A targeting aptamer was installed at a user-defined position using an octahedron as a model structure. Chemotherapeutic drug-loaded polyhedral objects were subsequently delivered into tumor cells. Furthermore, anticancer drug-loaded DNA octahedra were intravenously injected into a HeLa tumor-bearing mouse model. Assembly efficiency was almost 100 %, with no residual building blocks identified. Moreover, this nanotechnology required a few DNA oligonucleotides, even for complex polyhedrons. Symmetric DNA polyhedrons retained their structural integrity for 24 h in complex biological environments, guaranteeing prolonged circulation without drug leakage in the bloodstream and promoting efficient accumulation in tumor tissues. In addition, DNA octahedra were cleared relatively slowly from tumor tissues. Similarly, tumor growth was significantly inhibited in vivo, and a therapeutic outcome comparable to that of conventional gene-chemo combination therapy was observed. Moreover, no systemic toxicity was detected. These findings indicate the potential application of ZGC DNA nanotechnology in precision medicine.

A DNA-Modularized STING Agonist with Macrophage-Selectivity and Programmability for Enhanced Anti-Tumor Immunotherapy

The activation of cyclic GMP-AMP (cGAMP) synthase (cGAS) and its adaptor, stimulator of interferon genes (STING), is known to reprogram the immunosuppressive tumor microenvironment for promoting antitumor immunity. To enhance the efficiency of cGAS-STING pathway activation, macrophage-selective uptake, and programmable cytosolic release are crucial for the delivery of STING agonists. However, existing polymer- or lipid-based delivery systems encounter difficulty in integrating multiple functions meanwhile maintaining precise control and simple procedures. Herein, inspired by cGAS being a natural DNA sensor, a modularized DNA nanodevice agonist (DNDA) is designed that enable macrophage-selective uptake and programmable activation of the cGAS-STING pathway through precise self-assembly. The resulting DNA nanodevice acts as both a nanocarrier and agonist. Upon local administration, it demonstrates the ability of macrophage-selective uptake, endosomal escape, and cytosolic release of the cGAS-recognizing DNA segment, leading to robust activation of the cGAS-STING pathway and enhanced antitumor efficacy. Moreover, DNDA elicits a synergistic therapeutic effect when combined with immune checkpoint blockade. The study broadens the application of DNA nanotechnology as an immune stimulator for cGAS-STING activation.

Programmable Tetrahedral DNA-RNA Nanocages Woven with Stimuli-Responsive siRNA for Enhancing Therapeutic Efficacy of Multidrug-Resistant Tumors

Multidrug resistance (MDR) is a major obstacle limiting the effectiveness of chemotherapy against cancer. The combination strategy of chemotherapeutic agents and siRNA targeting drug efflux has emerged as an effective cancer treatment to overcome MDR. Herein, stimuli-responsive programmable tetrahedral DNA-RNA nanocages (TDRN) have been rationally designed and developed for dynamic co-delivery of the chemotherapeutic drug doxorubicin and P-glycoprotein (P-gp) siRNA. Specifically, the sense and antisense strand sequences of the P-gp siRNA, which are programmable bricks with terminal disulfide bond conjugation, are precisely embedded in one edge of the DNA tetrahedron. TDRN provides a stimuli-responsive release element for dynamic control of functional cargo P-gp siRNA that is significantly more stable than the "tail-like" TDN nanostructures. The stable and highly rigid 3D nanostructure of the siRNA-organized TDRN nanocages demonstrated a notable improvement in the stability of RNase A and mouse serum, as well as long-term storage stability for up to 4 weeks, as evidenced by this study. These biocompatible and multifunctional TDRN nanocarriers with gold nanocluster-assisted delivery (TDRN@Dox@AuNCp) are successfully used to achieve synergistic RNAi/Chemo-therapy in vitro and in vivo. This programmable TDRN drug delivery system, which integrates RNAi therapy and chemotherapy, offers a promising approach for treating multidrug-resistant tumors.

Advances in the study of S100A9 in cardiovascular diseases

Cardiovascular disease (CVD) is a group of diseases that primarily affect the heart or blood vessels, with high disability and mortality rates, posing a serious threat to human health. The causative factors, pathogenesis, and characteristics of common CVD differ, but they all involve common pathological processes such as inflammation, oxidative stress, and fibrosis. S100A9 belongs to the S100 family of calcium-binding proteins, which are mainly secreted by myeloid cells and bind to the Toll-like receptor 4 and receptor for advanced glycation end products and is involved in regulating pathological processes such as inflammatory response, fibrosis, vascular calcification, and endothelial barrier function in CVD. The latest research has found that S100A9 is a key biomarker for diagnosing and predicting various CVD. Therefore, this article reviews the latest research progress on the diagnostic and predictive, and therapeutic value of S100A9 in inflammatory-related CVD such as atherosclerosis, myocardial infarction, and arterial aneurysm and summarizes its molecular mechanisms in the progression of CVD, aiming to explore new predictive methods and to identify potential intervention targets for CVD in clinical practice.

Harnessing tetrahedral framework nucleic acids for enhanced delivery of microRNA-149-3p: A new frontier in oral squamous cell carcinoma therapy

Oral squamous cell carcinoma (OSCC), a type of malignant tumour that primarily occurs in the oral mucosa, has drawn considerable attention owing to its aggressive growth and potentially high metastatic rate. Surgical resection is the primary treatment method for OSCC and is typically combined with radiation therapy and chemotherapy. microRNA-149-3p (miR-149) is a negative regulator of the Pi3k/Akt pathway and can effectively inhibit the proliferation of tumour cells. However, the application of miR-149 is limited owing to its relatively low efficiency of cellular uptake and poor stability when used alone. To overcome these challenges, this study adopted a novel nucleic acid nanostructured material, tetrahedral framework nucleic acids (tFNAs). The use of tFNAs as carriers to assemble the T-miR-149 complex reduced the expression of Pi3k and Akt involved in tumorigenesis and alterations in proteins related to cell apoptosis. The results indicated that the bionic drug delivery system has an effective tumour suppressive effect on OSCC in mice, revealing its potential clinical value in the treatment of OSCC.

SLC25A19 is a novel prognostic biomarker related to immune invasion and ferroptosis in HCC

SLC25A19 is a mitochondrial thiamine pyrophosphate (TPP) carrier that mediates TPP entry into the mitochondria. SLC25A19 has been recognized to play a crucial role in many metabolic diseases, but its role in cancer has not been clearly reported. Based on clinical data from The Cancer Genome Atlas (TCGA), the following parameters were analyzed among HCC patients: SLC25A19 expression, enrichment analyses, immune infiltration, ferroptosis and prognosis analyses. In vitro, the SLC25A19 high expression was validated by qRT-PCR and Immunohistochemistry. Subsequently, a series of cell function experiments, including CCK8, EdU, clone formation, trans-well and scratch assays, were conducted to illustrate the effect of SLC25A19 on the growth and metastasis of cancer cells. Meanwhile, indicators related to ferroptosis were also detected. SCL25A19 is highly expressed in HCC and predicts a poor prognosis. Elevated SLC25A19 expression in HCC patients was markedly associated with T stage, pathological status (PS), tumor status (TS), histologic grade (HG), and AFP. Our results indicate that SLC25A19 has a generally good prognosis predictive and diagnostic ability. The results of gene enrichment analyses showed that SLC25A19 is significantly correlated with immune infiltration, fatty acid metabolism, and ferroptosis marker genes. In vitro experiments have confirmed that silencing SLC25A19 can significantly inhibit the proliferation and migration ability of cancer cells and induce ferroptosis in HCC. In conclusion, these findings indicate that SLC25A19 is novel prognostic biomarker related to immune invasion and ferroptosis in HCC, and it is an excellent candidate for therapeutic target against HCC.

Revolutionizing cancer therapy using tetrahedral DNA nanostructures as intelligent drug delivery systems

DNA nanostructures have surfaced as intriguing entities with vast potential in biomedicine, notably in the drug delivery area. Tetrahedral DNA nanostructures (TDNs) have received worldwide attention from among an array of different DNA nanostructures due to their extraordinary stability, great biocompatibility, and ease of functionalization. TDNs could be readily synthesized, making them attractive carriers for chemotherapeutic medicines, nucleic acid therapeutics, and imaging probes. Their varied uses encompass medication delivery, molecular diagnostics, biological imaging, and theranostics. This review extensively highlights the mechanisms of functional modification of TDNs and their applications in cancer therapy. Additionally, it discusses critical concerns and unanswered problems that require attention to increase the future application of TDNs in developing cancer treatment.

Self-assembled methodologies for the construction of DNA nanostructures and biological applications

Over the past decades, deoxyribonucleic acid (DNA), as a versatile building block, has been widely employed to construct functionalized nanostructures. Among the diverse types of materials, DNA related nanostructures have gained growing attention due to their intrinsic programmability, favorable biocompatibility, and strong molecular recognition capability. The conventional construction strategy for building DNA structures is based on Watson-Crick base-pairing rules, which are mainly driven by the hydrogen bonding of bases. However, hydrogen bonding-based DNA nanostructures cannot meet the requirements of specific morphology and multifunctionality. Currently, various functional elements have been introduced to expand the synthetic methodologies for constructing the DNA hybrid nanostructures, including small molecules, peptide polymers, organic ligands and transition metal ions. Besides, the potential applications for these DNA hybrid nanostructures have also been explored. It has been demonstrated that DNA hybrid structures with various properties can be extensively applied in the fields of magnetic resonance, luminescence imaging, biomedical detection, and drug delivery systems. In this review, we highlight the pioneering contributions to the methodologies of DNA-based nanostructure assembly. Furthermore, the recent advances in drug delivery systems and biomedical diagnosis based on DNA hybrid nanostructures are briefly summarized.

MicroRNA-29c-tetrahedral framework nucleic acids: Towards osteogenic differentiation of mesenchymal stem cells and bone regeneration in critical-sized calvarial defects

Certain miRNAs, notably miR29c, demonstrate a remarkable capacity to regulate cellular osteogenic differentiation. However, their application in tissue regeneration is hampered by their inherent instability and susceptibility to degradation. In this study, we developed a novel miR29c delivery system utilising tetrahedral framework nucleic acids (tFNAs), aiming to enhance its stability and endocytosis capability, augment the efficacy of miR29c, foster osteogenesis in bone marrow mesenchymal stem cells (BMSCs), and significantly improve the repair of critical-sized bone defects (CSBDs). We confirmed the successful synthesis and biocompatibility of sticky ends-modified tFNAs (stFNAs) and miR29c-modified stFNAs (stFNAs-miR29c) through polyacrylamide gel electrophoresis, microscopy scanning, a cell counting kit-8 assay and so on. The mechanism and osteogenesis effects of stFNAs-miR29c were explored using immunofluorescence staining, western blotting, and reserve transcription quantitative real-time polymerase chain reaction. Additionally, the impact of stFNAs-miR29c on CSBD repair was assessed via micro-CT and histological staining. The nano-carrier, stFNAs-miR29c was successfully synthesised and exhibited exemplary biocompatibility. This nano-nucleic acid material significantly upregulated osteogenic differentiation-related markers in BMSCs. After 2 months, stFNAs-miR29c demonstrated significant bone regeneration and reconstruction in CSBDs. Mechanistically, stFNAs-miR29c enhanced osteogenesis of BMSCs by upregulating the Wnt signalling pathway, contributing to improved bone tissue regeneration. The development of this novel nucleic acid nano-carrier, stFNAs-miR29c, presents a potential new avenue for guided bone regeneration and bone tissue engineering research.

Modulating Intracellular Dynamics for Optimized Intracellular Release and Transcytosis Equilibrium

Active transcytosis-mediated nanomedicine transport presents considerable potential in overcoming diverse delivery barriers, thereby facilitating tumor accumulation and penetration. Nevertheless, the persistent challenge lies in achieving a nuanced equilibrium between intracellular interception for drug release and transcytosis for tumor penetration. In this study, a comprehensive exploration is conducted involving a series of polyglutamine-paclitaxel conjugates featuring distinct hydrophilic/hydrophobic ratios (HHR) and tertiary amine-oxide proportions (TP) (OPGA-PTX). The screening process, meticulously focused on delineating their subcellular distribution, transcytosis capability, and tumor penetration, unveils a particularly promising candidate denoted as OPPX, characterized by an HHR of 10:1 and a TP of 100%. OPPX, distinguished by its rapid cellular internalization through multiple endocytic pathways, selectively engages in trafficking to the Golgi apparatus for transcytosis to facilitate accumulation within and penetration throughout tumor tissues and simultaneously sorted to lysosomes for cathepsin B-activated drug release. This study not only identifies OPPX as an exemplary nanomedicine but also underscores the feasibility of modulating subcellular distribution to optimize the active transport capabilities and intracellular release mechanisms of nanomedicines, providing an alternative approach to designing efficient anticancer nanomedicines.

DNA-based nanostructures for RNA delivery

RNA-based therapeutics have emerged as a promising approach for the treatment of various diseases, including cancer, genetic disorders, and infectious diseases. However, the delivery of RNA molecules into target cells has been a major challenge due to their susceptibility to degradation and inefficient cellular uptake. To overcome these hurdles, DNA-based nano technology offers an unprecedented opportunity as a potential delivery platform for RNA therapeutics. Due to its excellent characteristics such as programmability and biocompatibility, these DNA-based nanostructures, composed of DNA molecules assembled into precise and programmable structures, have garnered significant attention as ideal building materials for protecting and delivering RNA payloads to the desired cellular destinations. In this review, we highlight the current progress in the design and application of three DNA-based nanostructures: DNA origami, lipid-nanoparticle (LNP) technology related to frame guided assembly (FGA), and DNA hydrogel for the delivery of RNA molecules. Their biomedical applications are briefly discussed and the challenges and future perspectives in this field are also highlighted.

Gelatin-Encapsulated Tetrahedral DNA Nanostructure Enhances Cellular Internalization for Treating Noise-Induced Hearing Loss

Nanoparticle-based drug delivery strategies have emerged as a crucial avenue for comprehensive sensorineural hearing loss treatment. Nevertheless, developing therapy vectors crossing both biological and cellular barriers has encountered significant challenges deriving from various external factors. Herein, the rational integration of gelatin nanoparticles (GNPs) with tetrahedral DNA nanostructures (TDNs) to engineer a distinct drug-delivery nanosystem (designed as TDN@GNP) efficiently enhances the biological permeability and cellular internalization, further resolving the dilemma of noise-induced hearing loss via loading epigallocatechin gallate (EGCG) with anti-lipid peroxidation property. Rationally engineering of TDN@GNP demonstrates dramatic alterations in the physicochemical key parameters of TDNs that are pivotal in cell-particle interactions and promote cellular uptake through multiple endocytic pathways. Furthermore, the EGCG-loaded nanosystem (TDN-EGCG@GNP) facilitates efficient inner ear drug delivery by superior permeability through the biological barrier (round window membrane), maintaining high drug concentration within the inner ear. The TDN-EGCG@GNP actively overcomes the cell membrane, exhibiting hearing protection from noise insults via reduced lipid peroxidation in outer hair cells and spiral ganglion neurons. This work exemplifies how integrating diverse vector functionalities can overcome biological and cellular barriers in the inner ear, offering promising applications for inner ear disorders.

Selenium-Containing Nanocomplexes Achieve Dual Immune Checkpoint Blockade for NK Cell Reinvigoration

The blockade of immune checkpoints has emerged as a promising strategy for cancer immunotherapy. However, most of the current approaches focus on T cells, leaving natural killer (NK) cell-mediated therapeutic strategies rarely explored. Here, a selenium-containing nanocomplex is developed that acts as a dual immune checkpoint inhibitor to reinvigorate NK cell-based cancer immunotherapy. The Se nanocomplex can deliver and release siRNA that targets programmed death ligand-1 (PD-L1) in tumor cells, thereby silencing the checkpoint receptor PD-L1. The intracellular reactive oxygen species generated by porphyrin derivatives in the nanocomplexes can oxidize the diselenide bond into seleninic acid, which blocks the expression of another checkpoint receptor, human leukocyte antigen E. The blockade of dual immune checkpoints shows synergistic effects on promoting NK cell-mediated antitumoral activity. This study provides a new strategy to reinvigorate NK cell immunity for the development of combined cancer immunotherapy.

Framework nucleic acids as promising reactive oxygen species scavengers for anti-inflammatory therapy

Reactive oxygen species (ROS) are an array of derivatives of molecular oxygen that participate in multiple physiological processes under the control of redox homeostasis. However, under pathological conditions, the over-production of ROS often leads to oxidative stress and inflammatory reactions, indicating a potential therapeutic target. With the rapid development of nucleic acid nanotechnology, scientists have exploited various DNA nanostructures with remarkable biocompatibility, programmability, and structural stability. Among these novel organic nanomaterials, a group of skeleton-like framework nucleic acid (FNA) nanostructures attracts the most interest due to their outstanding self-assembly, cellular endocytosis, addressability, and functionality. Surprisingly, different FNAs manifest similarly satisfactory antioxidative and anti-inflammatory effects during their biomedical application process. First, they are intrinsically endowed with the ability to neutralize ROS due to their DNA nature. Therefore, they are extensively involved in the complicated inflammatory signaling network. Moreover, the outstanding editability of FNAs also allows for flexible modifications with nucleic acids, aptamers, peptides, antibodies, low-molecular-weight drugs, and so on, thus further strengthening the targeting and therapeutic ability. This review focuses on the ROS-scavenging potential of three representative FNAs, including tetrahedral framework nucleic acids (tFNAs), DNA origami, and DNA hydrogels, to summarize the recent advances in their anti-inflammatory therapy applications. Although FNAs exhibit great potential in treating inflammatory diseases as promising ROS scavengers, massive efforts still need to be made to overcome the emerging challenges in their clinical translation.

Tetrahedral framework nucleic acids/hyaluronic acid-methacrylic anhydride hybrid hydrogel with antimicrobial and anti-inflammatory properties for infected wound healing

Bacterial resistance and excessive inflammation are common issues that hinder wound healing. Antimicrobial peptides (AMPs) offer a promising and versatile antibacterial option compared to traditional antibiotics, with additional anti-inflammatory properties. However, the applications of AMPs are limited by their antimicrobial effects and stability against bacterial degradation. TFNAs are regarded as a promising drug delivery platform that could enhance the antibacterial properties and stability of nanodrugs. Therefore, in this study, a composite hydrogel (HAMA/t-GL13K) was prepared via the photocross-linking method, in which tFNAs carry GL13K. The hydrogel was injectable, biocompatible, and could be instantly photocured. It exhibited broad-spectrum antibacterial and anti-inflammatory properties by inhibiting the expression of inflammatory factors and scavenging ROS. Thereby, the hydrogel inhibited bacterial infection, shortened the wound healing time of skin defects in infected skin full-thickness defect wound models and reduced scarring. The constructed HAMA/tFNA-AMPs hydrogels exhibit the potential for clinical use in treating microbial infections and promoting wound healing.

DNA Nanospheres Assisted Spatial Confinement Signal Amplification for MicroRNA Imaging in Live Cancer Cells

DNA assemblies are commonly used in biosensing, particularly for the detection and imaging of microRNAs (miRNAs), which are biomarkers associated with tumor progression. However, the difficulty lies in the exploration of high-sensitivity analytical techniques for miRNA due to its limited presence in living cells. In this study, we introduced a DNA nanosphere (DS) enhanced catalytic hairpin assembly (CHA) system for the detection and imaging of intracellular miR-21. The single-stranded DNA with four palindromic portions and extending sequences at the terminal was annealed for assembling DS, which avoided the complex sequence design and high cost of long DNA strands. Benefiting from the multiple modification sites of DS, functional hairpins H1 (modified with Cy3 and BHQ2) and H2 were grafted onto the surface of DS for assembling DS-H1-H2 using a hybridization reaction. The DS-H1-H2 system utilized spatial confinement and the CHA reaction to amplify fluorescence signals of Cy3. This enabled highly sensitive and rapid detection of miR-21 in the range from 0.05 to 3.5 nM. The system achieved a limit of determination (LOD) of 2.0 pM, which was 56 times lower than that of the control CHA circuit with freedom hairpins. Additionally, the sensitivity was improved by 8 times. Moreover, DS-H1-H2 also showed an excellent imaging capability for endogenous miR-21 in tumor cells. This was due to enhanced cell internalization efficiency, accelerated reaction kinetics, and improved biostability. The imaging strategy was shown to effectively monitor the dynamic content of miR-21 in live cancer cells and differentiate various cells. In general, the simple nanostructure DS not only enhanced the detection and imaging capability of the conventional probe but also could be easily integrated with the reported DNA-free probe, indicating a wide range of potential applications.

A DNA tetrahedron-based ferroptosis-suppressing nanoparticle: superior delivery of curcumin and alleviation of diabetic osteoporosis

Diabetic osteoporosis (DOP) is a significant complication that poses continuous threat to the bone health of patients with diabetes; however, currently, there are no effective treatment strategies. In patients with diabetes, the increased levels of ferroptosis affect the osteogenic commitment and differentiation of bone mesenchymal stem cells (BMSCs), leading to significant skeletal changes. To address this issue, we aimed to target ferroptosis and propose a novel therapeutic approach for the treatment of DOP. We synthesized ferroptosis-suppressing nanoparticles, which could deliver curcumin, a natural compound, to the bone marrow using tetrahedral framework nucleic acid (tFNA). This delivery system demonstrated excellent curcumin bioavailability and stability, as well as synergistic properties with tFNA. Both in vitro and in vivo experiments revealed that nanoparticles could enhance mitochondrial function by activating the nuclear factor E2-related factor 2 (NRF2)/glutathione peroxidase 4 (GPX4) pathway, inhibiting ferroptosis, promoting the osteogenic differentiation of BMSCs in the diabetic microenvironment, reducing trabecular loss, and increasing bone formation. These findings suggest that curcumin-containing DNA tetrahedron-based ferroptosis-suppressing nanoparticles have a promising potential for the treatment of DOP and other ferroptosis-related diseases.

Chemically Modified Platforms for Better RNA Therapeutics

RNA-based therapies have catalyzed a revolutionary transformation in the biomedical landscape, offering unprecedented potential in disease prevention and treatment. However, despite their remarkable achievements, these therapies encounter substantial challenges including low stability, susceptibility to degradation by nucleases, and a prominent negative charge, thereby hindering further development. Chemically modified platforms have emerged as a strategic innovation, focusing on precise alterations either on the RNA moieties or their associated delivery vectors. This comprehensive review delves into these platforms, underscoring their significance in augmenting the performance and translational prospects of RNA-based therapeutics. It encompasses an in-depth analysis of various chemically modified delivery platforms that have been instrumental in propelling RNA therapeutics toward clinical utility. Moreover, the review scrutinizes the rationale behind diverse chemical modification techniques aiming at optimizing the therapeutic efficacy of RNA molecules, thereby facilitating robust disease management. Recent empirical studies corroborating the efficacy enhancement of RNA therapeutics through chemical modifications are highlighted. Conclusively, we offer profound insights into the transformative impact of chemical modifications on RNA drugs and delineates prospective trajectories for their future development and clinical integration.

DNA framework signal amplification platform-based high-throughput systemic immune monitoring

Systemic immune monitoring is a crucial clinical tool for disease early diagnosis, prognosis and treatment planning by quantitative analysis of immune cells. However, conventional immune monitoring using flow cytometry faces huge challenges in large-scale sample testing, especially in mass health screenings, because of time-consuming, technical-sensitive and high-cost features. However, the lack of high-performance detection platforms hinders the development of high-throughput immune monitoring technology. To address this bottleneck, we constructed a generally applicable DNA framework signal amplification platform (DSAP) based on post-systematic evolution of ligands by exponential enrichment and DNA tetrahedral framework-structured probe design to achieve high-sensitive detection for diverse immune cells, including CD4+, CD8+ T-lymphocytes, and monocytes (down to 1/100 μl). Based on this advanced detection platform, we present a novel high-throughput immune-cell phenotyping system, DSAP, achieving 30-min one-step immune-cell phenotyping without cell washing and subset analysis and showing comparable accuracy with flow cytometry while significantly reducing detection time and cost. As a proof-of-concept, DSAP demonstrates excellent diagnostic accuracy in immunodeficiency staging for 107 HIV patients (AUC > 0.97) within 30 min, which can be applied in HIV infection monitoring and screening. Therefore, we initially introduced promising DSAP to achieve high-throughput immune monitoring and open robust routes for point-of-care device development.

Simulation-Assisted DNA Nanodevice Serve as a General Optical Platform for Multiplexed Analysis of Micrornas

Small frame nucleic acids (FNAs) serve as excellent carrier materials for various functional nucleic acid molecules, showcasing extensive potential applications in biomedicine development. The carrier module and function module combination is crucial for probe design, where an improper combination can significantly impede the functionality of sensing platforms. This study explores the effect of various combinations on the sensing performance of nanodevices through simulations and experimental approaches. Variances in response velocities, sensitivities, and cell uptake efficiencies across different structures are observed. Factors such as the number of functional molecules loaded, loading positions, and intermodular distances affect the rigidity and stability of the nanostructure. The findings reveal that the structures with full loads and moderate distances between modules have the lowest potential energy. Based on these insights, a multisignal detection platform that offers optimal sensitivity and response speed is developed. This research offers valuable insights for designing FNAs-based probes and presents a streamlined method for the conceptualization and optimization of DNA nanodevices.

Spatiotemporally Programmed Disassembly of Multifunctional Integrated DNAzyme Nanoplatfrom for Amplified Intracellular MicroRNA Imaging

The sensing performance of DNAzymes in live cells is tremendously hampered by the inefficient and inhomogeneous delivery of DNAzyme probes and their incontrollable off-site activation, originating from their susceptibility to nuclease digestion. This requires the development of a more compact and robust DNAzyme-delivering system with site-specific DNAzyme activation property. Herein, a highly compact and robust Zn@DDz nanoplatform is constructed by integrating the unimolecular microRNA-responsive DNA-cleaving DNAzyme (DDz) probe with the requisite DNAzyme Zn2+ -ion cofactors, and the amplified intracellular imaging of microRNA via the spatiotemporally programmed disassembly of Zn@DDz nanoparticles is achieved. The multifunctional Zn@DDz nanoplatform is simply composed of a structurally blocked self-hydrolysis DDz probe and the inorganic Zn2+ -ion bridge, with high loading capacity, and can effectively deliver the initially catalytic inert DDz probe and Zn2+ into living cells with enhanced stabilities. Upon their entry into the acidic microenvironment of living cells, the self-sufficient Zn@DDz nanoparticle is disassembled to release DDz probe and simultaneously supply Zn2+ -ion cofactors. Then, endogenous microRNA-21 catalyzes the reconfiguration and activation of DDz for generating the amplified readout signal with multiply guaranteed imaging performance. Thus, this work paves an effective way for promoting DNAzyme-based biosensing systems in living cells, and shows great promise in clinical diagnosis.

Tetrahedral framework nucleic acid loaded with glabridin: A transdermal delivery system applicated to anti-hyperpigmentation

Topical application of tyrosinase inhibitors, such as hydroquinone and arbutin, is the most common clinical treatment for hyperpigmentation. Glabridin (Gla) is a natural isoflavone that inhibits tyrosinase activity, free radical scavenging, and antioxidation. However, its water solubility is poor, and it cannot pass through the human skin barrier alone. Tetrahedral framework nucleic acid (tFNA), a new type of DNA biomaterial, can penetrate cells and tissues and can be used as carriers to deliver small-molecule drugs, polypeptides, and oligonucleotides. This study aimed to develop a compound drug system using tFNA as the carrier to transport Gla and deliver it through the skin to treat pigmentation. Furthermore, we aimed to explore whether tFNA-Gla can effectively alleviate the hyperpigmentation caused by increased melanin production and determine whether tFNA-Gla exerts substantial synergistic effects during treatment. Our results showed that the developed system successfully treated pigmentation by inhibiting regulatory proteins related to melanin production. Furthermore, our findings showed that the system was effective in treating epidermal and superficial dermal diseases. The tFNA-based transdermal drug delivery system can thus develop into novel, effective options for non-invasive drug delivery through the skin barrier.

Transcutaneous Immunotherapy for RNAi: A Cascade-Responsive Decomposable Nanocomplex Based on Polyphenol-Mediated Framework Nucleic Acid in Psoriasis

Skin is the first barrier against external threats, and skin immune dysfunction leads to multiple diseases. Psoriasis is an inflammatory, chronic, common, immune-related skin disease that affects more than 125 million people worldwide. RNA interference (RNAi) therapy is superior to traditional therapies, but rapid degradation and poor cell uptake are the greatest obstacles to its clinical transformation. The transdermal delivery of siRNA and controllable assembly/disassembly of nanodrug delivery systems can maximize the therapeutic effect. Tetrahedral framework nucleic acid (tFNA) is undoubtedly the best carrier for the transdermal transport of genes due to its excellent noninvasive transdermal effect and editability. The authors combine acid-responsive tannic acid (TA), RNase H-responsive sequences, siRNA, and tFNA into a novel transdermal RNAi drug with controllable assembly and disassembly: STT. STT has heightened resistance to enzyme, serum, and lysosomal degradation, and its size is similar to that of tFNA, enabling easy transdermal transport. After transdermal administration, STT can specifically silence nuclear factor kappa-B (NF-κB) p65, thereby maintaining the stability of the skin's microenvironment and reshaping normal skin immune defense. This work demonstrates the advantages of STT in RNAi therapy and the potential for future treatment of skin-related diseases.

Multifunctional MXene-Based Bioactive Materials for Integrated Regeneration Therapy

The reconstruction engineering of tissue defects accompanied by major diseases including cancer, infection, and inflammation is one of the important challenges in clinical medicine. The development of innovative tissue engineering strategies such as multifunctional bioactive materials presents a great potential to overcome the challenge of disease-impaired tissue regeneration. As the major representative of two-dimensional nanomaterials, MXenes have shown multifunctional physicochemical properties and have been diffusely studied as multimodal nanoplatforms in the field of biomedicine. This review summarized the recent advances in the multifunctional properties of MXenes and integrated regeneration-therapy applications of MXene-based biomaterials, including tissue regeneration-tumor therapy, tissue regeneration-infection therapy, and tissue regeneration-inflammation therapy. MXenes have been recognized as good candidates for promoting tissue regeneration and treating diseases through photothermal therapy, regulating cell behavior, and drug and gene delivery. The current challenges and future perspectives of MXene-based biomaterials in integrated regeneration-therapy are also discussed well in this review. In summary, MXene-based biomaterials have shown promising potential for integrated tissue regeneration and disease treatment due to their favorable physicochemical properties and bioactive functions. However, there are still many obstacles and challenges that must be addressed for the regeneration-therapy applications of MXene-based biomaterials, including understanding the bioactive mechanism, ensuring long-term biosafety, and improving their targeting therapy capacity.

RNA Nanomedicine: Delivery Strategies and Applications

Delivery of RNA using nanomaterials has emerged as a new modality to expand therapeutic applications in biomedical research. However, the delivery of RNA presents unique challenges due to its susceptibility to degradation and the requirement for efficient intracellular delivery. The integration of nanotechnologies with RNA delivery has addressed many of these challenges. In this review, we discuss different strategies employed in the design and development of nanomaterials for RNA delivery. We also highlight recent advances in the pharmaceutical applications of RNA delivered via nanomaterials. Various nanomaterials, such as lipids, polymers, peptides, nucleic acids, and inorganic nanomaterials, have been utilized for delivering functional RNAs, including messenger RNA (mRNA), small interfering RNA, single guide RNA, and microRNA. Furthermore, the utilization of nanomaterials has expanded the applications of functional RNA as active pharmaceutical ingredients. For instance, the delivery of antigen-encoding mRNA using nanomaterials enables the transient expression of vaccine antigens, leading to immunogenicity and prevention against infectious diseases. Additionally, nanomaterial-mediated RNA delivery has been investigated for engineering cells to express exogenous functional proteins. Nanomaterials have also been employed for co-delivering single guide RNA and mRNA to facilitate gene editing of genetic diseases. Apart from the progress made in RNA medicine, we discuss the current challenges and future directions in this field.

The nano-windmill exerts superior anti-inflammatory effects via reducing choline uptake to inhibit macrophage activation

Macrophages' activation plays a central role during the development and progression of inflammation, while the regulation of metabolic reprogramming of macrophages has been recently identified as a novel strategy for anti-inflammatory therapies. Our previous studies have found that tetrahedral framework nucleic acid (tFNA) plays a mild anti-inflammatory effect by inhibiting macrophage activation, but the specific mechanism remains unclear. Here, by metabolomics and RNA sequencing, choline uptake is identified to be significantly repressed by decreased slc44a1 expression in tFNA-treated activated macrophages. Inspired by this result, combined with the excellent delivery capacities of tFNA, siR-slc44a1 is loaded into the tFNA to develop a new tFNA-based small interfering RNA (siRNA) delivery system named 'nano-windmill,' which exhibits a synergetic role by targeting slc44a1, finally blowing up the anti-inflammatory effects of tFNA to inhibit macrophages activation via reducing choline uptake. By confirming its anti-inflammatory effects in chronic (periodontitis) and acute (sepsis) inflammatory disease, the tFNA-based nanomedicine developed for inflammatory diseases may provide broad prospects for tFNA upgrading and various biological applications such as anti-inflammatory.

Unraveling the Possibilities: Recent Progress in DNA Biosensing

Due to the advantages of its numerous modification sites, predictable structure, high thermal stability, and excellent biocompatibility, DNA is the ideal choice as a key component of biosensors. DNA biosensors offer significant advantages over existing bioanalytical techniques, addressing limitations in sensitivity, selectivity, and limit of detection. Consequently, they have attracted significant attention from researchers worldwide. Here, we exemplify four foundational categories of functional nucleic acids: aptamers, DNAzymes, i-motifs, and G-quadruplexes, from the perspective of the structure-driven functionality in constructing DNA biosensors. Furthermore, we provide a concise overview of the design and detection mechanisms employed in these DNA biosensors. Noteworthy advantages of DNA as a sensor component, including its programmable structure, reaction predictility, exceptional specificity, excellent sensitivity, and thermal stability, are highlighted. These characteristics contribute to the efficacy and reliability of DNA biosensors. Despite their great potential, challenges remain for the successful application of DNA biosensors, spanning storage and detection conditions, as well as associated costs. To overcome these limitations, we propose potential strategies that can be implemented to solve these issues. By offering these insights, we aim to inspire subsequent researchers in related fields.

Functional micro-RNA drugs acting as a fate manipulator in the regulation of osteoblastic death

Bone loss is prevalent in clinical pathological phenomena such as osteoporosis, which is characterized by decreased osteoblast function and number, increased osteoclast activity, and imbalanced bone homeostasis. However, current treatment strategies for bone diseases are limited. Regulated cell death (RCD) is a programmed cell death pattern activated by the expression of specific genes in response to environmental changes. Various studies have shown that RCD is closely associated with bone diseases, and manipulating the death fate of osteoblasts could contribute to effective bone treatment. Recently, microRNA-targeting therapy drugs have emerged as a potential solution because of their precise targeting, powerful curative effect, and limited side effects. Nevertheless, their clinical application is limited by their inherent instability, easy enzymatic degradation, and poor membrane penetrability. To address this challenge, a self-assembling tetrahedral DNA nanostructure (TDN)-based microRNA (Tmi) delivery system has been proposed. TDN features excellent biocompatibility, cell membrane penetrability, serum stability, and modification versatility, making it an ideal nucleic acid carrier for miRNA protection and intracellular transport. Once inside cells, Tmi can dissociate and release miRNAs to manipulate key molecules in the RCD signaling pathway, thereby regulating bone homeostasis and curing diseases caused by abnormal RCD activation. In this paper, we discuss the impact of the miRNA network on the initiation and termination of four critical RCD programs in bone tissues: apoptosis, autophagy, pyroptosis, and ferroptosis. Furthermore, we present the Tmi delivery system as a miRNA drug vector. This provides insight into the clinical translation of miRNA nucleic acid drugs and the application of miRNA drugs in bone diseases.

Biomimetic nanoparticles targeting atherosclerosis for diagnosis and therapy

Atherosclerosis is a typical chronic inflammatory vascular disease that seriously endangers human health. At present, oral lipid-lowering or anti-inflammatory drugs are clinically used to inhibit the development of atherosclerosis. However, traditional oral drug treatments have problems such as low utilization, slow response, and serious side effects. Traditional nanodrug delivery systems are difficult to interactively recognize by normal biological organisms, and it is difficult to target the delivery of drugs to target lesions. Therefore, building a biomimetic nanodrug delivery system with targeted drug delivery based on the pathological characteristics of atherosclerosis is the key to achieving efficient and safe treatment of atherosclerosis. In this review, various nanodrug delivery systems that can target atherosclerosis are summarized and discussed. In addition, the future prospects and challenges of its clinical translation are also discussed.

Intracellular activated logic nanomachines based on framework nucleic acids for low background detection of microRNAs in living cells

DNA molecular machines based on DNA logic circuits show unparalleled potential in precision medicine. However, delivering DNA nanomachines into real biological systems and ensuring that they perform functions specifically, quickly and logically remain a challenge. Here, we developed an efficient DNA molecular machine integrating transfer-sensor-computation-output functions to achieve high fidelity detection of intracellular biomolecules. The introduction of pH nanoswitches enabled the nanomachines to be activated after entering the cell, and the spatial-confinement effect of the DNA triangular prism (TP) enables the molecular machine to process complex information at the nanoscale, with higher sensitivity and shorter response time than diffuse-dominated logic circuits. Such cascaded activation molecular machines follow the logic of AND to achieve specific capture and detection of biomolecules in living cells through a multi-hierarchical response, providing a new insight into the construction of efficient DNA molecular machines.

Recent progress and application of the tetrahedral framework nucleic acid materials on drug delivery

INTRODUCTION

The application of DNA framework nucleic acid materials in the biomedical field has witnessed continual expansion. Among them, tetrahedral framework nucleic acids (tFNAs) have gained significant traction as the foremost biological vectors due to their superior attributes of editability, low immunogenicity, biocompatibility, and biodegradability. tFNAs have demonstrated promising results in numerous in vitro and in vivo applications.

AREAS COVERED

This review summarizes the latest research on tFNAs in drug delivery, including a discussion of the advantages of tFNAs in regulating biological behaviors, and highlights the updated development and advantageous applications of tFNAs-based nanostructures from static design to dynamically responsive design.

EXPERT OPINION

tFNAs possess distinct biological regulatory attributes and can be taken up by cells without the requirement of transfection, differentiating them from other biological vectors. tFNAs can be easily physically/chemically modified and seamlessly incorporated with other functional systems. The static design of the tFNAs-based drug delivery system makes it versatile, reproducible, and predictable. Further use of the dynamic response mechanism of DNA to external stimuli makes tFNAs-based drug delivery more effective and specific, improving the uptake and utilization of the payload by the intended target. Dynamic targeting is poised to become the future primary approach for drug delivery.

Tetrahedral framework nucleic acids inhibit pathological neovascularization and vaso-obliteration in ischaemic retinopathy via PI3K/AKT/mTOR signalling pathway

This study aimed to explore the effect and the molecular mechanism of tetrahedral framework nucleic acids (tFNAs), a novel self-assembled nanomaterial with excellent biocompatibility and superior endocytosis ability, in inhibition of pathological retinal neovascularization (RNV) and more importantly, in amelioration of vaso-obliteration (VO) in ischaemic retinopathy. tFNAs were synthesized from four single-stranded DNAs (ssDNAs). Cell proliferation, wound healing and tube formation assays were performed to explore cellular angiogenic functions in vitro. The effects of tFNAs on reducing angiogenesis and inhibiting VO were explored by oxygen-induced retinopathy (OIR) model in vivo. In vitro, tFNAs were capable to enter endothelial cells (ECs), inhibit cell proliferation, tube formation and migration under hypoxic conditions. In vivo, tFNAs successfully reduce RNV and inhibit VO in OIR model via the PI3K/AKT/mTOR/S6K pathway, while vascular endothelial growth factor fusion protein, Aflibercept, could reduce RNV but not inhibit VO. This study provides a theoretical basis for the further understanding of RNV and suggests that tFNAs might be a novel promising candidate for the treatment of blind-causing RNV.

DNA Tetrahedra-Based Delivery of MicroRNA-22 to Reduce Depressive Symptoms in Mice

Major depressive disorder (MDD) is a common illness with an increasing lifetime prevalence. Thus, an increasing number of studies have investigated the association between MDD and microRNAs (miRNAs), which are a novel approach for treating depression. However, the therapeutic potential of miRNA-based strategies has several limitations. To overcome these limitations, DNA tetrahedra (TDNs) have been used as piggyback materials. In this study, we successfully used TDNs as carriers of miRNA-22-3p (miR-22-3p) and synthesized a novel DNA nanocomplex (TDN-miR-22-3p), which was used in a lipopolysaccharide (LPS)-induced depression cell model. The results suggest that miR-22-3p may regulate inflammation by regulating phosphatase and tensin homologue (PTEN), an important regulatory molecule in the PI3K/AKT pathway, and downregulating the expression of NLRP3. We further validated the role of TDN-miR-22-3p in vivo using an LPS-induced animal model of depression. The results indicate that it ameliorated depression-like behavior and attenuated the expression of inflammation-related factors in mice. This study demonstrates the establishment of a straightforward and efficacious miRNA delivery system and the potential of TDNs as therapeutic vectors and tools for mechanistic studies. To the best of our knowledge, this is the first study to use TDNs in combination with miRNAs to treat depression.

Rigidity-Dependent Emission: Inspired Selection of an ATP-Specific Polyvalent Hydrogen Binding-Lighted Fluorophore for Intracellular Amplified Imaging

ATP, a small molecule with high intracellular concentration (mM level), provides a fuel to power signal amplification, which is meaningful for biosensing. However, traditional ATP-powered amplification is based on ATP/aptamer recognition, which is susceptible to the complex biological microenvironment (e.g., nuclease). In this work, we communicate a signaling manner termed as ATP-specific polyvalent hydrogen binding (APHB), which is mimetic to ATP/aptamer binding but can avoid interference from biomolecules. The key in APHB is a functional fluorophore that can selectively bind with ATP via polyvalent hydrogen, and the fluorescence was lighted with the changes of the molecular structure from flexibility to rigidity. By designing, synthesizing, and screening a series of compounds, we successfully obtained an ATP-specific binding-lighted fluorophore (ABF). Experimental verification and a complex analogue demonstrated that two melamine brackets in the ABF dominate the polyvalent hydrogen binding between the ABF and ATP. Then, to achieve amplification biosensing, fibroblast activation protein (FAP) in activated hepatic stellate cells was taken as a model target, and a nanobeacon consisting of an ABF, a quencher, and an FAP-activated polymer shell was constructed. Benefiting from the ATP-powered amplification, the FAP was sensitively detected and imaged, and the potential relationship between differentiation of hepatocytes and FAP concentration was first revealed, highlighting the great potential of APHB-mediated signaling for intracellular sensing.

Typhaneoside-Tetrahedral Framework Nucleic Acids System: Mitochondrial Recovery and Antioxidation for Acute Kidney Injury treatment

Acute kidney injury (AKI) is not only a worldwide problem with a cruel hospital mortality rate but also an independent risk factor for chronic kidney disease and a promoting factor for its progression. Despite supportive therapeutic measures, there is no effective treatment for AKI. This study employs tetrahedral framework nucleic acid (tFNA) as a vehicle and combines typhaneoside (Typ) to develop the tFNA-Typ complex (TTC) for treating AKI. With the precise targeting ability on mitochondria and renal tubule, increased antiapoptotic and antioxidative effect, and promoted mitochondria and kidney function restoration, the TTC represents a promising nanomedicine for AKI treatment. Overall, this study has developed a dual-targeted nanoparticle with enhanced therapeutic effects on AKI and could have critical clinical applications in the future.

Nano shield: a new tetrahedral framework nucleic acids-based solution to radiation-induced mucositis

Radiation-induced oral mucositis (RIOM) is considered to be one of the most important public health problems today, affecting the overall well-being of millions of patients who have received radiotherapy. Nevertheless, the field of preventing and treating RIOM is still widely unexplored. Curcumin (Cur) with its promising anti-inflammatory and antioxidant properties is accompanied with obstacles in application, including poor dissolubility, instability and low bioavailability. In this study, a tetrahedral framework nucleic acid drug delivery system (TFNAS) was synthesized and established using a novel method to carry Cur (Cur-TFNAS) for efficient drug delivery. The results showed that Cur-TFNAS enhanced the antioxidant capacity of human oral mucosal keratin-forming cells (HOKs) compared to free Cur and TFNAS. Meanwhile, Cur-TFNAS reduced DNA damage and shielded the cells from inflammatory factors. A similar result was also well documented in vivo. Herein, we consider that Cur-TFNAS acts as a nano-shield for preventing radiation oral mucositis and shows important clinical value in the future.

Hydrogel Drug Delivery Systems for Bone Regeneration

With the in-depth understanding of bone regeneration mechanisms and the development of bone tissue engineering, a variety of scaffold carrier materials with desirable physicochemical properties and biological functions have recently emerged in the field of bone regeneration. Hydrogels are being increasingly used in the field of bone regeneration and tissue engineering because of their biocompatibility, unique swelling properties, and relative ease of fabrication. Hydrogel drug delivery systems comprise cells, cytokines, an extracellular matrix, and small molecule nucleotides, which have different properties depending on their chemical or physical cross-linking. Additionally, hydrogels can be designed for different types of drug delivery for specific applications. In this paper, we summarize recent research in the field of bone regeneration using hydrogels as delivery carriers, detail the application of hydrogels in bone defect diseases and their mechanisms, and discuss future research directions of hydrogel drug delivery systems in bone tissue engineering.

Small interfering RNA-based nanotherapeutics for treating skin-related diseases

INTRODUCTION

RNA interference (RNAi) has demonstrated great potential in treating skin-related diseases, as small interfering RNA (siRNA) can efficiently silence specific genes. The design of skin delivery systems for siRNA is important to protect the nucleic acid while facilitating both skin targeting and cellular ingestion. Entrapment of siRNA into nanocarriers can accomplish these aims, contributing to improved targeting, controlled release, and increased transfection.

AREAS COVERED

The siRNA-based nanotherapeutics for treating skin disorders are summarized. First, the mechanisms of RNAi are presented, followed by the introduction of challenges for skin therapy. Then, the different nanoparticle types used for siRNA skin delivery are described. Subsequently, we introduce the mechanisms of how nanoparticles enhance siRNA skin penetration. Finally, the current investigations associated with nanoparticulate siRNA application in skin disease management are reviewed.

EXPERT OPINION

The potential application of nanotherapeutic RNAi allows for a novel skin application strategy. Further clinical studies are required to confirm the findings in the cell-based or animal experiments. The capability of large-scale production and reproducibility of nanoparticle products are also critical for translation to commercialization. siRNA delivery by nanocarriers should be optimized to attain cutaneous targeting without the risk of toxicity.

Engineering Circular Aptamer Assemblies with Tunable Selectivity to Cell Membrane Antigens In Vitro and In Vivo

The strategy of enhancing molecular recognition by improving the binding affinity of drug molecules against targets has generated a lot of successful therapeutic applications. However, one critical consequence of such affinity improvement, generally called "on-target, off-tumor" toxicity, emerged as a major obstacle limiting their clinical usage. Herein, we provide a modular assembly strategy that affords affinity-tunable DNA nanostructures allowing for immobilizing multiple aptamers that bind to the example antigen of EpCAM with different affinities. We develop a theoretical model proving that the apparent affinity of aptamer assemblies to target cells varies with antigen density as well as aptamer valency. More importantly, we demonstrate experimentally that the theoretical model can be used to predict the least valency required for discrimination between EpCAM^high and EpCAM^low cells in vitro and in vivo. We believe that our strategy will have broad applications in an engineering nucleic acid-based delivery platform for targeted and cell therapy.

Osteochondral Interface: Regenerative Engineering and Challenges

Osteochondral (OC) defects are debilitating for patients and represent a significant clinical problem for orthopedic surgeons as well as regenerative engineers due to their potential complications, which are likely to lead to osteoarthritis and related diseases. If they remain untreated or are treated suboptimally, OC lesions are known to impact the articular cartilage and the transition from cartilage to bone, that is, the cartilage-bone interface. An important component of the OC interface, that is, a selectively permeable membrane, the tidemark, still remains unaddressed in more than 90% of the published research in the past decade. This review focuses on the structure, composition, and function of the OC interface, regenerative engineering attempts with different scaffolding strategies and challenges ahead of us in recapitulating the native OC interface. There are different schools of thought regarding the structure of the native OC interface: stratified and graded. The former assumes the cartilage-to-bone interface to be hierarchically divided into distinct yet continuous zones of uncalcified cartilage-calcified cartilage-subchondral bone. The latter assumes the interface is continuously graded, that is, formed by an infinite number of layers. The cellular composition of the interface, either in respective layers or continuously changing in a graded manner, is chondrocytes, hypertrophic chondrocytes, and osteoblasts as moved from cartilage to bone. Functionally, the interface is assumed to play a role in enabling a smooth transition of loads exerted on the cartilage surface to the bone underneath. Regenerative engineering involves, first, a characterization of the native OC interface in terms of the composition, structure, and function, and, then, proposes the appropriate biomaterials, cells, and biomolecules either alone or in combination to eventually form a structure that mimics and functionally behaves similar to the native interface. The major challenge regarding regeneration of the OC interface appears to lie, in addition to others, in the formation of tidemark, which is a thin membrane separating the OC interface into two distinct zones: the avascular OC interface and the vascular OC interface. There is a significant amount of literature on regenerative approaches to the OC interface; however, only a small portion of them consider the importance of tidemark. Therefore, this review aims at highlighting the significance of the structural organization of the components of the OC interface and increasing the awareness of the orthopedics community regarding the importance of tidemark formation after clinical interventions or regenerative engineering attempts.

Tetrahedral framework nucleic acid nanomaterials reduce the inflammatory damage in sepsis by inhibiting pyroptosis

Sepsis is a highly lethal condition and is caused by the dysregulation of the body's immune response to infection. Indeed, sepsis remains the leading cause of death in severely ill patients, and currently, no effective treatment is available. Pyroptosis, which is mainly activated by cytoplasmic danger signals and eventually promote the release of the pro-inflammatory factors, is a newly discovered programmed cell death procedure that clears infected cells while simultaneously triggering an inflammatory response. Increasing evidence indicates that pyroptosis participates in the development of sepsis. As a novel DNA nanomaterial, tetrahedral framework nucleic acids (tFNAs) characterized by its unique spatial structure, possess an excellent biosafety profile and can quickly enter the cell to impart anti-inflammatory and anti-oxidation effects. In this study, the roles of tFNAs in the in vitro model of macrophage cell pyroptosis and in the in vivo model of septic mice were examined, and it was found that tFNAs could mitigate organ inflammatory damage in septic mice, wherein they reduced inflammatory factor levels by inhibiting pyroptosis. These results provide possible new strategies for the future treatment of sepsis.

Tetrahedral-Framework Nucleic Acid Loaded with MicroRNA-155 Enhances Immunocompetence in Cyclophosphamide-Induced Immunosuppressed Mice by Modulating Dendritic Cells and Macrophages

Nanomaterials are often used as immunomodulators because they can be tailored by a controllable process. In this work, a complex based on a tetrahedral framework nucleic acid delivery system and MicroRNA-155, known as T-155, is synthesized for the modulation of immunosuppression. In vivo, T-155 ameliorated spleen and thymus damage and hematopoiesis suppression in cyclophosphamide-induced immunosuppressed mice by promoting T-cell proliferation to resist oxidative stress. In vitro, T-155 induced immature dendritic cells (DCs) to differentiate into mature DCs by the ERK1/2 pathway and converted M0 macrophages (Mφ) into the M1 type by the NF-κB pathway to enhance the surveillance capabilities of antigen-presenting cells. The experimental results suggest that T-155 has therapeutic potential as an immunomodulator for immunosuppression.

An in situ protonation-activated supramolecular self-assembly for selective suppression of tumor growth

An in situ supramolecular self-assembly in the subcellular organelles could provide a new strategy to treat diseases. Herein, we report a protonation-activated in situ supramolecular self-assembly system in the lysosomes, which could destabilize the lysosome membrane, resulting in the selective suppression of cancer cells. In this system, pyridyl-functionalized tetraphenylethylene (TPE-Py) was protonated in the lysosomes of A549 lung cancer cells to form octahedron-like structures with cucurbit[8]uril (CB[8]), which impaired the integrity of the lysosome membrane, resulting in selective suppression of cancer cells. Moreover, its anticancer efficiency was also systematically evaluated in vivo, triggering the apoptosis of tumor tissues with ignorable effects on normal organs. Overall, the protonation-activated self-assembly in the lysosomes based on the host-guest complexation would provide a method for novel anti-cancer systems.

Functional nucleic acids as potent therapeutics against SARS-CoV-2 infection

The COVID-19 pandemic has posed a severe threat to human life and the global economy. Although conventional treatments, including vaccines, antibodies, and small-molecule inhibitors, have been broadly developed, they usually fall behind the constant mutation of SARS-CoV-2, due to the long screening process and high production cost. Functional nucleic acid (FNA)-based therapeutics are a newly emerging promising means against COVID-19, considering their timely adaption to different mutants and easy design for broad-spectrum virus inhibition. In this review, we survey typical FNA-related therapeutics against SARS-CoV-2 infection, including aptamers, aptamer-integrated DNA frameworks, functional RNA, and CRISPR-Cas technology. We first introduce the pathogenesis, transmission, and evolution of SARS-CoV-2, then analyze the existing therapeutic and prophylactic strategies, including their pros and cons. Subsequently, the FNAs are recommended as potent alternative therapeutics from their screening process and controllable engineering to effective neutralization. Finally, we put forward the remaining challenges of the existing field and sketch out the future development directions.

Virus Mimetic Framework DNA as a Non-LNP Gene Carrier for Modulated Cell Endocytosis and Apoptosis

Mimicking the size and shape of spherical viruses, we constructed a soccer-ball shaped virus-inspired DNA origami (ViDO) framework as a programmable non-LNP (lipid nanoparticle) gene carrier. The DNA framework was decorated with precisely controlled recognition molecules outside and loaded with adequate genetic molecules inside. Five variants were constructed to systematically investigate their cell uptake and modulated gene silencing efficiency. Cellular uptake was enhanced with an increasing number of aptamers, while with a median number of aptamer supply, dispersed distribution performed better than the clustered pattern. Intriguingly, the transfection efficiency was maximized using the ViDO with clustered five aptamers, which exhibited a competitive RNA silencing effect induced by Lipo2000 with low cytotoxicity. Our results revealed the effects of aptamer distribution patterns on endocytosis and transfection, thus providing a programmable platform for meticulous optimization of the gene delivery system.

Tetrahedral Framework Nucleic Acids: A Novel Strategy for Antibiotic Treating Drug-Resistant Infections

Antibiotic multiresistance (AMR) has emerged as a major threat to human health as millions of people die from AMR-related problems every year. As has been witnessed during the global COVID-19 pandemic, the significantly increased demand for antibiotics has aggravated the issue of AMR. Therefore, there is an urgent need to find ways to alleviate it. Tetrahedral framework nucleic acids (tFNAs) are novel nanomaterials that are often used as drug delivery platforms because of their structural diversity. This study formed a tFNAs-antibiotic compound (TAC) which has a strong growth inhibitory effect on Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) in vitro owing to the increased absorption of antibiotics by bacteria and improved drug movement across cell membranes. We established a mouse model of systemic peritonitis and local wound infections. The TAC exhibited good biosafety and improved the survival rate of severely infected mice, promoting the healing of local infections. In addition to the better transport of antibiotics to the target, the TAC may also enhance immunity by regulating the differentiation of M1 and M2 macrophages, providing a new option for the treatment of infections.

Insight on nano drug delivery systems with targeted therapy in treatment of oral cancer

Oral cancer is a type of cancer that develops in the mouth and is one of the deadliest malignancies in the world. Currently surgical, radiation therapy, and chemotherapy are most common treatments. Better treatment and early detection strategies are required. Chemotherapeutic drugs fail frequently due to toxicity and poor tumor targeting. There are high chances of failure of chemotherapeutic drugs due to toxicity. Active, passive, and immunity-targeting techniques are devised for tumor-specific activity. Nanotechnology-based drug delivery systems are the best available solution and important for precise targeting. Nanoparticles, liposomes, exosomes, and cyclodextrins are nano-based carriers for drug delivery. Nanotechnology is being used to develop new techniques such as intratumoral injections, microbubble mediated ultrasonic therapy, phototherapies, and site-specific delivery. This systematic review delves into the details of such targeted and nano-based drug delivery systems in order to improve patient health and survival rates in oral cancer.

A dynamic DNA tetrahedron framework for active targeting

An active targeting strategy-enabled DNA tetrahedron delivery vehicle could facilitate stable drug encapsulation and stimuli-responsive on-demand release, building a universal platform for different drug delivery requirements. Owing to the excellent biocompatible nature, programmability and remarkable cell and tissue permeability, the tetrahedral DNA nanostructure (TDN) has proven its value in the delivery of various bioactive molecules. We previously described this as a static multifunctional complex in our earlier protocol. However, static structures and passive targeting behavior might introduce off-target effects under complicated biological conditions. Therefore, in this Protocol Extension, we present a major update of the TDN delivery vehicle enabling an active targeting strategy to be used for stimuli-sensitive conformation changes and on-site cargo release, which could avoid drawbacks, including complex and time-consuming fabrication processes and undetermined cell penetration ability of other DNA-based delivery vehicles. Upon exquisite design of TDN size based on cargo type, one-pot annealing is applied to fabricate the Tiamat-designed TDN exoskeleton. Then the design of the dynamic DNA apparatus can be based on the target and environmental stimuli, including DNA strand hybridization-based and pH-sensitive DNA apparatus, and careful titration of strand lengths and mismatches is achieved using polyacrylamide and agarose gel electrophoresis, or fluorophore modifications. Finally, cargo loading strategies are designed, including site and stand titration and cargo encapsulation verification. The dynamic structures show promising targetability and effectiveness in antitumor and anti-inflammatory treatment in vitro and in vivo. Assembly and characterization in the lab takes ~5 d, and the timing for the verification of biostability and biological applications depends on the uses.

Cationic lipid modification of DNA tetrahedral nanocages enhances their cellular uptake

Self-assembled DNA nanocages are among the most promising candidates for bioimaging and payload delivery into cells. DNA nanocages have great potential to efficiently address drug resistance and nucleic acid delivery problems due to precise control of their shape and size, and excellent biocompatibility. Although DNA nanostructures demonstrate some cellular uptake, because they bear a highly negative charge, the uptake of tetrahedral nanostructures is hindered by electrostatic repulsion. In this study, we describe a method to enhance the cellular uptake of DNA nanostructures using a binary system containing DNA and a positively charged head group with a hydrophobic lipid chain containing lipids for cellular internalization. Here we represent the functionalization of a model cage, DNA tetrahedron (TD) with a cationic lipid, N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTMA). Atomic force microscopy (AFM) and other standard characterization techniques were used to explore the co-assembly of the DNA tetrahedron and DOTMA. We revealed a simple confocal microscopy-based approach to show the enhancement in the cellular uptake of DNA nanocages. This new method will find multiple applications in delivery applications such as gene transfection, drug delivery and targeted bioimaging.

Improved Tumor Infiltration and Immunomodulation for Tumor Therapy: A Pathway Based on Tetrahedral Framework Nucleic Acids Coupled Bacterial Nanocells

Growing evidence indicates that the tumor microenvironment (TME) can be combined with other therapeutic modalities, including cytotoxic chemotherapy and targeted therapies, to produce unanticipated results in oncology treatment. Here, we proposed a novel bacterial nanomaterial capable of targeting peritumoral biofilm and modulating TME. It was based on tetrahedral framework nucleic acids (T) that were chemically attached to aptamer AS1411 and 5-fluorouracil (AT5). Additionally, the oral pathogenic bacterium Streptococcus mutans (S.m) was employed as a biocarrier for synergetic biofilm targeting and immunomodulation. In this article, the effect of AT5-coupled S.m-derived nanocells (S.m-AT5) was investigated in vitro and in vivo. Due to bacteria aggregation in the tumor-specific biofilm, these nanocells released greater medication concentrations. Furthermore, they exerted an immunomodulatory effect by stimulating the maturation of dendritic cells (DCs) and regulation of T cells. This chemo-immunostimulation combination has a powerful antitumor impact. It may also be an advanced approach for boosting the survival rate of cancer patients.